This anonymous Commentary is printed from Troyes, Bibl. munic. 658, a manuscript written at Clairvaux in the late 12th century.It is well known that St Bernard in 1147 revised the monastic hymnal for the use of his Cistercian monks; the anonymous Explanatio is primary evidence for the content of Bernard's hymnal. It is also an invaluable index of Cistercian spirituality in the late 12th century, and provides an index of the range of reading of a Cistercian scholar of that time.